react-security

Prevent XSS, secure auth flows, and harden React client-side applications. Use when preventing XSS, securing auth flows, or auditing third-party dependencies in React. (triggers: **/*.tsx, **/*.jsx, dangerouslySetInnerHTML, token, auth, xss)

385 stars

Best use case

react-security is best used when you need a repeatable AI agent workflow instead of a one-off prompt.

Prevent XSS, secure auth flows, and harden React client-side applications. Use when preventing XSS, securing auth flows, or auditing third-party dependencies in React. (triggers: **/*.tsx, **/*.jsx, dangerouslySetInnerHTML, token, auth, xss)

Teams using react-security should expect a more consistent output, faster repeated execution, less prompt rewriting.

When to use this skill

  • You want a reusable workflow that can be run more than once with consistent structure.

When not to use this skill

  • You only need a quick one-off answer and do not need a reusable workflow.
  • You cannot install or maintain the underlying files, dependencies, or repository context.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/react-security/SKILL.md --create-dirs "https://raw.githubusercontent.com/HoangNguyen0403/agent-skills-standard/main/skills/react/react-security/SKILL.md"

Manual Installation

  1. Download SKILL.md from GitHub
  2. Place it in .claude/skills/react-security/SKILL.md inside your project
  3. Restart your AI agent — it will auto-discover the skill

How react-security Compares

Feature / Agentreact-securityStandard Approach
Platform SupportNot specifiedLimited / Varies
Context Awareness High Baseline
Installation ComplexityUnknownN/A

Frequently Asked Questions

What does this skill do?

Prevent XSS, secure auth flows, and harden React client-side applications. Use when preventing XSS, securing auth flows, or auditing third-party dependencies in React. (triggers: **/*.tsx, **/*.jsx, dangerouslySetInnerHTML, token, auth, xss)

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

Related Guides

SKILL.md Source

# React Security

## **Priority: P0 (CRITICAL)**

Preventing vulnerabilities in client-side apps.

## Prevent XSS Attacks

- **Never use `dangerouslySetInnerHTML`** without sanitization. Use **`DOMPurify.sanitize(input)`** for all user-provided HTML.
- Avoid `javascript:` protocols in `href` or `src`.

See [implementation examples](references/REFERENCE.md#xss-prevention-with-dompurify) for DOMPurify sanitization and secure cookie configuration.

## Secure Authentication

- Store **JWT/Sessions in `HttpOnly` and `Secure` cookies** to prevent theft via XSS. **Never store secrets in `localStorage`** or in the built JS bundle.
- **Data Flow**: **Escape all serialized state** if injecting into the HTML (e.g., in SSR). Use a **Content Security Policy (CSP)** to restrict script sources and prevent inline execution.

## Harden Application Boundaries

- **CSRF Protection**: Use **CSRF tokens** for state-changing requests (PUT/POST/DELETE). Implement **SameSite=Strict** cookies where applicable.
- **Input Sanitization**: Always **validate and sanitize** user inputs on the backend. Frontend validation is for UX only.
- **Dependency Management**: Run **`npm audit` / `pnpm audit`** regularly. Pin specific dependency versions and use **`npm-check-updates`**.
- **Security Headers**: Ensure the server sends **`X-Frame-Options: DENY`**, **`X-Content-Type-Options: nosniff`**, and **`Permissions-Policy`**.

## Anti-Patterns

- **No `eval()`**: RCE risk.
- **No Serialized State**: Don't inject JSON into DOM without escaping.
- **No Client Logic for Permissions**: Backend must validate.

## References

See [references/REFERENCE.md](references/REFERENCE.md) for DOMPurify usage, CSP headers, OAuth2/JWT auth patterns, and CSRF protection.

Related Skills

spring-boot-security

385
from HoangNguyen0403/agent-skills-standard

Configure Spring Security 6+ with Lambda DSL, JWT, and hardening rules. Use when configuring Spring Security 6+, OAuth2, JWT, or security hardening in Spring Boot. (triggers: **/*SecurityConfig.java, **/*Filter.java, security-filter-chain, lambda-dsl, csrf, cors)

react-typescript

385
from HoangNguyen0403/agent-skills-standard

Type React components and hooks with TypeScript patterns. Use when typing React props, hooks, event handlers, or component generics in TypeScript. (triggers: **/*.tsx, ReactNode, FC, PropsWithChildren, ComponentProps)

react-tooling

385
from HoangNguyen0403/agent-skills-standard

Configure debugging, bundle analysis, and ecosystem tools for React applications. Use when setting up Vite/webpack build tooling, analyzing bundle size, debugging re-renders with React DevTools, or configuring ESLint and StrictMode for React projects. (triggers: package.json, devtool, bundle, strict mode, profile)

react-testing

385
from HoangNguyen0403/agent-skills-standard

Test React components with RTL and Jest/Vitest. Use when writing React component tests with React Testing Library, Jest, or Vitest. (triggers: **/*.test.tsx, **/*.spec.tsx, render, screen, userEvent, expect)

react-state-management

385
from HoangNguyen0403/agent-skills-standard

Select and implement local, global, and server state patterns in React. Use when choosing or implementing state management (Context, Zustand, Redux, React Query) in React. (triggers: **/*.tsx, **/*.jsx, state, useReducer, context, store, props)

react-performance

385
from HoangNguyen0403/agent-skills-standard

Optimize React rendering, bundle size, and data fetching performance. Use when optimizing React rendering performance, reducing re-renders, or improving bundle size. (triggers: **/*.tsx, **/*.jsx, waterfall, bundle, lazy, suspense, dynamic)

react-hooks

385
from HoangNguyen0403/agent-skills-standard

Write efficient React functional components and hooks. Use when writing custom hooks, optimizing useEffect, or working with useMemo/useCallback in React. (triggers: **/*.tsx, **/*.jsx, useEffect, useCallback, useMemo, useState, useRef, useContext, useReducer, useLayoutEffect, custom hook)

react-component-patterns

385
from HoangNguyen0403/agent-skills-standard

Build modern React component architecture with composition patterns. Use when designing reusable React components, applying composition patterns, or structuring component hierarchies. (triggers: **/*.jsx, **/*.tsx, component, props, children, composition, hoc, render-props)

react-native-testing

385
from HoangNguyen0403/agent-skills-standard

Test React Native components with Jest and React Native Testing Library. Use when writing Jest or React Native Testing Library tests for React Native components. (triggers: **/*.test.tsx, **/*.spec.tsx, __tests__/**, test, testing, jest, render, fireEvent, waitFor)

react-native-styling

385
from HoangNguyen0403/agent-skills-standard

Style React Native apps with StyleSheet API, Flexbox, theming, and responsive design. Use when implementing React Native styles, theming, Flexbox layouts, or responsive design. (triggers: **/*.tsx, **/*.ts, StyleSheet, style, theme, responsive, flexbox)

react-native-state-management

385
from HoangNguyen0403/agent-skills-standard

Implement local and global state with Context, Zustand, and Redux Toolkit in React Native. Use when choosing or implementing state management in React Native with Context, Zustand, or Redux. (triggers: **/*.tsx, **/*.ts, useState, useContext, zustand, redux, state-management)

react-native-security

385
from HoangNguyen0403/agent-skills-standard

Secure storage, network traffic, and deep links in React Native mobile apps. Use when implementing secure storage, certificate pinning, or deep link validation in React Native. (triggers: **/*.tsx, **/*.ts, security, keychain, secure-storage, deep-link, certificate-pinning)